Congratulations on the '68 Sprite, Marty! I have one of those too!
The hard-copy (as opposed to the cyber copy) of the Moss catalog has a section on deciphering the VIN numbers. Have you checked that yet?
On to the switches....
On the dash, left to right...The blower fan switch - either on or off (one speed) - - On the steering column cowl, left side, is a toggle switch for the dashboard lights - - On the right is the headlight switch, one click for parking lights and two clicks for the headlights.
The lever switch on the left of the dash cowl is multi-function. Pull toward you to momentarily flash high and low beams simultaneously, push away from you to turn on high beams. Push the lever switch in (toward the column) to beep the horn. Up and down for directionals.
The lever switch on the right of the column is the wiper switch- two speeds here, slow and not as slow! Push that lever in for the washer pump.
All the way on the left side of the dash is the heater air control. If turned counter-clockwise, the fresh air in will be on - clock-wise turns the fresh air off. There is no temperature control in the cockpit. Hot water to the heater matrix is controlled via a brass valve, just behind the valve cover under the bonnet.
As far as a REAL owners manual, EBay usually has that stuff but you can also buy the "Heritage Motor Centre" CD ROM from Moss. Among original service and parts guides, they have a PDF of the original owner's book too. (well at least the one I bought for my '76 Midget does).
Good luck with the car...I'm sure that you'll enjoy it!
On their death bed, nobody ever said, "Gee I wish I'd spent more time at work!"
'68 Sprite 1275
'76 Midget 1500